Make cheap magnetic LEDs for fun graffiti projects

Mark Frauenfelder:
The Make blog has an item about “LED Throwies,” made by a group with a wonderful name: Graffiti Research Lab.

200602141748 LED Throwies are an inexpensive way to add color to any ferromagnetic surface in your neighborhood. A Throwie consists of a lithium battery, a 10mm diffused LED and a rare-earth magnet taped together. Throw it up high and in quantity to impress your friends and city officials.

Link

see also this whimsical video at http://www.graffitiresearchlab.com/

Via Boing Boing